Multimodality Treatment for Women With Stage II, Stage III, or Stage IV Breast Cancer

OBJECTIVES: * Determine the cardiac and other toxicity of paclitaxel when administered with trastuzumab (Herceptin) after doxorubicin and cyclophosphamide in women with stage IIB, IIIA, IIIB, IIIC, or previously untreated stage IV breast cancer. * Determine whether the addition of paclitaxel with or without trastuzumab to conventional breast cancer adjuvant therapy (doxorubicin and cyclophosphamide) further decreases tumor size and the number of positive axillary nodes in these patients. * Determine the 5-year disease-free survival and overall survival of patients treated with these regimens. * Determine whether the initial pathologic response in patients receiving neoadjuvant therapy correlates with the eventual 5-year disease-free survival or overall survival. * Compare the number of patients eligible for breast-conserving cancer surgery after treatment with doxorubicin and cyclophosphamide vs paclitaxel and trastuzumab. * Correlate clinical and radiographic response rate with pathologic response rate in the primary tumor and axillary lymph nodes and determine which parameter best determines the pathologic response rate in patients treated with these regimens. OUTLINE: Patients either received neoadjuvant therapy (HER-2 overexpressing and non-overexpressing patients) or adjuvant therapy (HER-2 overexpressing patients only). * Neoadjuvant therapy: Patients receive one of two treatment regimens. * Regimen I (HER-2 non-overexpressing patients or HER-2 overexpressing patients who refuse trastuzumab (Herceptin) therapy): Patients receive doxorubicin IV and cyclophosphamide IV over 30 minutes and paclitaxel IV over 3 hours on day 1 every 3 weeks for a total of 4 courses. Patients then undergo surgery with or without adjuvant radiotherapy and/or oral tamoxifen. * Regimen II (HER-2 overexpressing patients only): Patients receive doxorubicin and cyclophosphamide as in regimen I. After completion of course 4, patients receive paclitaxel IV and trastuzumab IV over 90-150 minutes weekly on weeks 13-24. Patients then undergo surgery with or without adjuvant radiotherapy. Patients then receive trastuzumab IV over 30 minutes weekly on weeks 29-69 if they did not receive radiotherapy or on weeks 36-76 if they did receive radiotherapy. * Adjuvant therapy: Patients who receive adjuvant therapy (HER-2 overexpressing patients only) receive doxorubicin IV and cyclophosphamide IV over 30 minutes on day 1 every 3 weeks for a total of 4 courses. After completion of course 4, patients receive paclitaxel IV and trastuzumab IV over 90 minutes weekly on weeks 13-24. Patients then may undergo radiotherapy followed by trastuzumab IV over 30 minutes weekly on weeks 29-69 if they did not receive radiotherapy or on weeks 36-76 if they did receive radiotherapy. Patients are followed every 3 months for 2 years, every 6 months for 3 years, and then annually for 5 years. PROJECTED ACCRUAL: A total of 125 patients (100 in the neoadjuvant group and 25 in the adjuvant group) will be accrued for this study within 5 years.